The model below represents a nuclear reaction. atom 1 is present before the reaction and atom 2 and atom 3 are produced after the reaction.

atom 1 = atom 2 + atom 3 + energy

the model most likely represents a reaction which
select one:
a. takes place when atoms combine
b. takes place when atoms become inactive
c. does not produce energy in the sun
d. does not produce energy in nuclear power plants

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

your parents i think this could be it